Steve Nebraska's character is loosely based on a pitcher named Steve Dalkowski. But, unfortunately he never made it to the major leagues.
The film had a long development history. Peter Falk was cast as Al Percolo in 1983. In 1989, Rodney Dangerfield was attached to play Al with Sam Kinison attached to play Steve Nebraska.
The crowd and overhead shots at Yankee Stadium for Tommy Lacy's scenes during the day and when Steve Nebraska makes his debut during the World Series are from the 1993 season when the Yankees hosted the Detroit Tigers at the end of the season.
When Steve Nebraska is pitching in front of baseball scouts at Yankee Stadium, during filming Keith Hernandez walked out of the dugout wearing tennis shoes. Yankee owner George Steinbrenner told Hernandez to put on spiked shoes so he doesn't mess up the grass.
The Steve Nebraska try out scene at Yankee stadium was filmed Monday April 11th 1994. Bret Saberhagen was currently on the New York Mets roster that season and while he was at Yankee stadium shooting his scene the New York Mets were hosting the Chicago Cubs in the home opener at Shea Stadium. First pitch time for that game was 1:35 pm and Saberhagen shot his scene at Yankee stadium and made it to Shea Stadium during the game and was even spotted in the Mets dugout that day.